Otitis Media

 

Picture above shows Acute otitis media - Myringitis bullosa

 

 

Causes?

The common cause of all forms of otitis media is blockage of the Eustachian tube

    • This is usually due to swelling of the mucous membranes in the nasopharynx, which in turn can be caused by a viral upper respiratory infection or by allergies.
    • The blockage of the Eustachian tube, the air volume in the middle ear is trapped and parts of it are slowly absorbed by the surrounding tissues, leading to a mild vacuum in the middle ear.

    Picture above shows acute otitis media

     

     

    How it happen?

    Eventually the vacuum can reach a point where fluid from the surrounding tissues is sucked in to the middle ear's cavity (also called tympanic cavity), causing middle ear effusion. This is seen as a progression from a Type A tympanogram to a Type C to a Type B tympanogram.

     

     

     

    Picture above shows Otitis media chronica mesotympanalis

     

     

     

    Ways of spreading

    By reflux or suction of material from the nasopharynx into the normally sterile middle ear space, the fluid may then become infected - usually with bacteria.


     

     

    Extra Info

    In rare cases, however, the virus that caused the initial upper respiratory tract infection can itself be identified as the pathogen causing the infection in the middle ear.

     

     

     

     

    COMPARISON BETWEEN NORMAL EARS AND EARS WITH OTITIS MEDIA